(edit... ok, Mike and I wrote our posts at the same time... just as I thought!)
Both Chris and I started flying Revs just last year. We both have a bunch and I have purchased virtually every Rev that's out there...I love having them all but I could have gotten by with much less...
Here's my personal recommendations based on my experience and pocketbook considerations. I'm sure Mike and Chris will chime in here..
For Chicago, there are only 3 required...
1) 1.5 SUL
2) 1.5 SLE or B-Series... Personally, Chris and I prefer the B Series
3) 1.5 SLE or B-Series Vented.
It's all you really need. In fact, if you can handle a Rev without smashing it into the ground, the SUL and Vented may be all that you ever need.
For my tastes though:
1) 1.5 SUL - Great all around, low wind kite. Rev recommends < 8mph winds (I believe). We fly ours in heavier winds... most of the time, you can use the SUL up to the point of flying a vented. Myself, I prefer to only use the SUL in the lightest winds per Rev recommendations. But that's just me.
2) 90% of my flying is with the Standard B-Series. Because it comes with 2 frames (2 wrap and 3 wrap), it will handle most everything we experience here in the Chicago area until you get to 10+ mph winds. It's fast, crisp and great fun to fly. Very similar to the 1.5 SLE other than price and accessories. Considering that you get handles/2 frames, etc, the price, while close to $300, is a great deal. If you do decide to go with a 1.5 SLE though, be sure to request it with the 1/4" frameset. If you need more information, please ask..
3) on occasional days, +10mph winds are handled incredibly well by a vented. 10 is my low end with a 2 wrap frame but when we do get those higher wind speed days, there is nothing better than the vented for precision and control and fun.
If it were me, and I was sure that I was going to take flying seriously, and I could afford it, I would get the Standard B-Series to start with. If money is the issue, then the SUL is the way to go.
I will caution you on light wind flying though. Just because you get a SUL does not mean that flying in light wind is going to be effortless and easy. Light winds are tricky and typically involve lulls of no wind and shifting wind. Light wind flying is also a learned art form. Experience in normal winds is what will help you in the light winds.
I will also say that you will have to have patience and a resolve to learn to fly. Please feel free to use us and our experience to help you along. Flying with us or someone else experienced will help you grasp the basics quickly and hopefully prevent any frustration that would make you want to stop.
as for where to buy? Give Dave over at Chicago Kite a call. Tell him exactly what you want and he will get it for you if he doesn't have it in stock. His pricing is as good or better than anywhere else on the net. If you have any questions at all